Maidul Haque S, De Rajnarayan, Tripathi S, Mukherjee C, Yadav A K, Bhattacharyya Dibyendu, Jha S N, Sahoo N K
Appl Opt. 2017 Aug 1;56(22):6114-6125. doi: 10.1364/AO.56.006114.
Gadolinium oxide is an excellent optical material that offers high transmission in a wide wavelength range of 200-1600 nm and exhibits a high bulk refractive index of ∼1.80 at 550 nm. In the present study, a set of GdO thin films has been deposited on fused silica substrates by RF sputtering of a GdO target under various O to Ar flow ratios. The samples have been characterized by grazing incidence x-ray diffraction (GIXRD) to study the long range structural behavior, by GIXR to study density and surface roughness of the films, by atomic force microscopy measurements to study morphological properties, by Rutherford backscattering measurements for compositional studies, and by transmission spectrophotometry and spectroscopic ellipsometry techniques to study their optical properties. It has been observed that the films deposited with 10% oxygen partial pressure have low density, high surface roughness, and high void content, which results in a low value of refractive index of this film, and film quality improves as oxygen partial pressure is further increased. Extended x-ray absorption fine structure measurement with synchrotron radiation has also been employed to extract local structural information around Gd sites, which has in turn been used to explain some of the observed macroscopic properties of the films.
氧化钆是一种优异的光学材料，在200 - 1600纳米的宽波长范围内具有高透过率，在550纳米处呈现约1.80的高体折射率。在本研究中，通过在不同氧气与氩气流量比下对氧化钆靶材进行射频溅射，在熔融石英衬底上沉积了一组氧化钆薄膜。通过掠入射X射线衍射（GIXRD）研究薄膜的长程结构行为，通过掠入射X射线反射（GIXR）研究薄膜的密度和表面粗糙度，通过原子力显微镜测量研究薄膜的形貌特性，通过卢瑟福背散射测量进行成分研究，以及通过透射分光光度法和光谱椭偏测量技术研究其光学性质。已观察到，在10%氧气分压下沉积的薄膜密度低、表面粗糙度高且孔隙率高，这导致该薄膜的折射率值较低，并且随着氧气分压进一步增加，薄膜质量得到改善。还采用了同步辐射扩展X射线吸收精细结构测量来提取钆位点周围的局部结构信息，进而用于解释薄膜一些观察到的宏观性质。
